算法-队列

队列的介绍

队列（Queue），是一种线性存储结构。它有以下几个特点：
(01) 队列中数据是按照"先进先出（FIFO, First-In-First-Out）"方式进出队列的。
(02) 队列只允许在"队首"进行删除操作，而在"队尾"进行插入操作。
队列通常包括的两种操作：入队列和出队列。

1. 队列的示意图

队列中有10，20，30共3个数据。

2. 出队列

出队列前：队首是10，队尾是30。
出队列后：出队列(队首)之后。队首是20，队尾是30。

3. 入队列

入队列前：队首是20，队尾是30。
入队列后：40入队列(队尾)之后。队首是20，队尾是40。

用c语言实现一个可以容纳任何数据的队列实现

  1 /*
  2  * name :queue.c
  3  * description:    queue 
  4  *            single list 
  5  *@istta
  6  * Email: hcu5555@hotmail.com
  7  */
  8 
  9 #include <stdio.h>
 10 #include <stdlib.h>
 11 #include "queue.h"
 12 
 13 static struct queue_info * creat_node(void * data)
 14 {
 15     struct queue_info * new_node = NULL;
 16     new_node = (struct queue_info *)malloc(sizeof(struct queue_info));
 17     if(new_node ==NULL){
 18         printf("%s malloc error\n", __FUNCTION__);
 19         return NULL;
 20     }
 21     else{
 22         new_node->data = data; 
 23         new_node->next = NULL;
 24     }
 25 
 26     return new_node;
 27 }
 28 
 29 int  queue_init()
 30 {
 31     queue_single_list = creat_node(NULL);
 32     if(queue_single_list == NULL)
 33     {
 34         printf("creat queue is error\n");
 35         return -1;
 36     }
 37     queue_count = 0;
 38     printf("init queue\n");
 39     return 0;
 40 }
 41 
 42 
 43 int  queue_push(void * val)
 44 {
 45     if(queue_count == 0)
 46     {
 47         printf("queue is empty\n");
 48         queue_single_list = creat_node(val);
 49         if(queue_single_list == NULL)
 50         {
 51             printf("creat node head fail \n");
 52             return -1;
 53         }
 54         
 55         queue_count++;    
 56         return  0;
 57     }
 58 
 59     if(queue_count >=queue_max)
 60     {
 61         printf("queue is ful\n");
 62         return 0;
 63     }
 64 
 65     struct queue_info *p_node = creat_node(val);
 66     struct queue_info *p_end = queue_single_list;
 67 
 68     while(p_end->next)
 69         p_end= p_end->next;
 70 
 71     p_end->next = p_node;
 72     queue_count++;
 73     
 74     return 0;
 75 }
 76 
 77 void * queue_pop()
 78 {
 79     void * ret;
 80     ret = queue_single_list->data;
 81 
 82     struct queue_info * p_node;
 83     p_node = queue_single_list;
 84     queue_single_list = p_node->next;
 85     free(p_node);
 86 
 87     queue_count--;
 88     return ret;
 89 }
 90 
 91 int queue_is_empty()
 92 {
 93     return queue_count;
 94 }
 95 
 96 int queue_size()
 97 {
 98     int count= 0;
 99     struct queue_info * p_node = queue_single_list;
100     while(p_node)
101     {
102         count++;
103         p_node=p_node->next;
104     }
105     
106     return count;
107 }
108 
109 void * queue_front()
110 {
111     return queue_single_list->data;
112 }

queue.c

/*
 * name :queue.h
 * description:    queue 
 *            single list 
 *@istta
 * Email: hcu5555@hotmail.com
 */

 #ifndef __QUEUE_H__
 #define __QUEUE_H__

#ifdef cplusplus
extern "C" {
#endif

struct queue_info
{
    void * data;
    struct queue_info *next;
};

struct queue_info *queue_single_list;  
int queue_count;
int queue_max;

int  queue_init();
int queue_push(void *pval);
void  *queue_pop();
int queue_size();
int queue_is_empty();
void * queue_front();

#ifdef cplusplus
}
#endif

 #endif

queue.h

测试代码：

#include <stdio.h>
#include <stdlib.h>
#include "queue.h"

struct end_joined
{
    unsigned int device_id;
};

struct end_leave
{
    unsigned int device_id;
};

struct check
{
    unsigned int  coord_id;
    unsigned int  endd_id;
};


int main(void)
{
    struct end_joined  a;
    struct end_leave  b;
    struct check   c;

    a.device_id = 50004;
    b.device_id = 50004;
    c.coord_id = 50004;
    c.endd_id = 3;

    queue_max = 3;
    queue_init();
    printf("queue is %s\n", ((queue_is_empty()) == 0 )? "is empty" : "is not empty");

    if(queue_push(&a) !=0)
        printf("queue push is error\n");
    if(queue_push(&b) !=0)
        printf("queue push is error\n");
    printf("queue is %s\n", ((queue_is_empty()) == 0 )? "is empty" : "is not empty");        
    printf("queue size is %d\n", queue_size());

    struct end_joined *tmp = NULL;
    tmp = (struct end_joined *)queue_pop();
    printf("device_id %d\n", tmp->device_id);

    if(queue_push(&c) !=0)
        printf("queue push is error\n");
    struct end_leave *tmp2 = NULL;
    tmp2 = (struct end_leave *)queue_pop();
    printf("device_id %d\n", tmp->device_id);    
    printf("queue size is %d\n", queue_size());

    struct check  *tmp3;
    tmp3 = (struct check *)queue_pop();
    printf("device_id %d, port %d\n", tmp3->coord_id ,tmp3->endd_id);
    printf("queue size is %d\n", queue_size());

//    queue_max = 3;
//    int i =0 ;
    
    queue_push(&a);
    queue_push(&a);
    queue_push(&a);
    queue_push(&a);
    queue_push(&b);
    queue_push(&c);
    printf("queue size is %d\n", queue_size());

    
//    struct check *d, *f, * h, *g;
//    queue_push(d);
//    queue_push(f);
//    queue_push(h);
//    queue_push(g);
    
    return 0;
}

test.c

posted on 2014-04-03 16:56 hcu5555 阅读(124) 评论(0) 编辑收藏举报